To demonstrate, try just placing the pieces on the board to form a checkmate. Even with the lone King stuck in the corner, there is always one free square:

[fen]k7/8/K1B5/8/8/8/8/8[/fen]

[fen]k7/8/KN6/8/8/8/8/8[/fen]

Proof: No matter where he is on the board, the black King always has at least a 2x2 square to move around i ...[text shortened]... uares on the same rank [or file], but a Knight and Bishop can't. Thus, checkmate is impossible.

Oh oh, I think I see a board with four black Kings on it. I'm suspecting an illegal position! Have fertility drugs arrived in chess?